Phosphorus diamide ligands

Chart 6.8 Phosphorus diamide ligands studied by van Leeuwen et al. 

Study of Bulky Phosphorus Diamide Ligands 2S7 Table 6.8 IR frequencies obtained in the stoichiometric reaction of 18b (L = 17b), 1-octene, CO... 

Selective monosubstitution in the starting dibromide by PPh2 was realized at lowtemperatures [71]. Conversion of the second bromo substituent into the phosphorus diamide and final reaction with the diol produced the hybrid ligand. In the hydroformylation of 2,5-dihydrofuran, up to 91% ee with no isomerization was achieved, which is the best value reported to date. Noteworthy, the partially hydrogenated binaphthyl unit and the phenyl substituents in the 3,3 -positions are essential for the success of the asymmetric catalysis. Related ligands with a binaphthyl backbone, with or without Me-substituents in 3,3 -positions, resulted in poor conversions and stereoselectivities. 

The review begins with a selective summary of the history of organome-taUic and reductive rare-earth chemistry as an introduction to bimetallic lanthanide complexes bridged by ligands derived from arenes and to complexes of ferrocene-based diamide ligands, a major subtheme in the chapter. Detailed discussions then follow on complexes derived from fused rings and their reactivity with phosphorus and on complexes derived from biphenyl and stilbene as substrates, with emphasis on ferrocene-based diamide complexes. 

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